Higher data rates and better quality of service (QoS) are being sought for data communication over AC power lines. New protocols that offer such improvements will preferably be capable of coexisting with existing power line communication protocols such as HomePlug 1.0. Higher data rates and better quality of service (QoS) are typically important to both in-home and Internet-access communications (those between a home and an Internet service provider). One example of the latter is Broadband over Powerline (BPL), which is being proposed for Internet access using low voltage or medium voltage power lines.